"We expect the economic benefits for city-centre businesses to continue through Sunday and beyond as visitors slowly unwind from game night and move on to their next destination."
Police are urging motorists to be careful and take it slow on the convoy northwards from Wellington so everyone gets to Auckland safely.
Inspector Peter McKennie said the flood of vehicles would include more than 1000 camper vans, many of which would be carrying international visitors who will stop off at tourist spots along the way.
He urged people to slow down and be patient.
"Most are likely to head straight up the centre of the North Island, but many will take the opportunity to sight-see on their way to Auckland, including visiting the east and west coasts. Others might also venture north of Auckland while they wait for the final test to roll around.
"Whether you're a visiting British and Irish Lions fan or a local, we're encouraging everyone on the roads to be patient and courteous and drive to the conditions.
"Many drivers aren't aware that they can be travelling at the speed limit and still be at risk. The speed limit is the maximum legal speed that you can travel at on a road in ideal conditions. It is not a target."
McKennie said some larger camper vans are restricted to 90km/h on the open road, and with an increased number on the move, journeys might take slightly longer than usual. He warned motorists not to dangerously overtake and for camper vans to pull over when they could.
"It's important not to become frustrated by a slightly slower travel speed, and people certainly shouldn't allow frustration to lead to risk taking.
"A 10km/h difference in travel speed makes a maximum difference of only about 30 seconds for every 10 kilometres travelled, so behaviours such as overtaking at high speed or when it is unsafe are just not worth the risk.
"If you are part of a group travelling together in camper vans, then it's much better to arrange places to meet along the way and stagger your departure times to help ease congestion and delays."
McKennie says other key safety measures include wearing restraints, not driving after drinking alcohol and being aware of the risks of distraction and fatigue.
Lions fans visiting from overseas should also remember that New Zealand roads can often be narrow and winding, and our unique geography and weather conditions mean journeys can often take longer than they might at home.
Meanwhile this weekend has been the busiest ever for Wellington Airport.
An airport spokeswoman said 22,000 travelled through the airport on Saturday and 23,000 on Sunday after the game.
The spokeswoman said the airport was busy today, but flights were departing on time. Travellers are being advised to arrive earlier than normal and to expect queues when checking in and dropping off baggage.
A number of venues have been set up to accommodate Lions fans in their campervans.
Alexandra Park sales and marketing manager Joel Reichardt said they're expecting repeat visitors who stayed during the build up to the first test.
"The Lions fans have been all round lovely guests and a lot of fun.
"They're grateful for our staff help, pleased with our set up, and respectful to other park users. We will be welcoming them back with open arms this weekend," Reichardt said.
Fans wishing to stay at Alexandra Park will be charged $100 per night for a self-contained campervan for two people, with an extra $15 for each additional guest.
Reichardt said campers will be offered "plenty" of toilets and showers, dumping facilities, charging stations and on-site security.
On the Friday night before the final game 100 sites for campervans will be made available at Alexandra Park, with that number doubling to 200 on game day.